The present invention relates to the field of autoalignment systems for high power lasers and more particularly to autoalignment systems utilizing a separate alignment laser.
In many present and potential high power laser applications, it is necessary to control the direction of output beam propagation to within a few micro radians. Even in applications involving immobile, terrestial operation in a semi laboratory environment, the requirements for micro radian accuracy involve alignment system compensation for such low frequency laser beam drifts as (a) temperature variations of mirror mounts, piers and foundations, (b) metallic "creep" of mirror mounts and optical bench structures, (c) mechanical load variations on mirrors and mirror mounts due to cooling water pressure and flow and (d) relative displacement of building floors and foundations due to variations of temperature, soil humidity and atmospheric pressure. In view of the operational time involved in manual techniques for obtaining such alignment precision, the development of systems for automatically aligning high power lasers is of current interest. The high power levels involved, however, preclude the use of straight forward optical techniques, such as beam splitting or beam sampling.